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1.
Physically based simulation of human hair is a well studied and well known problem. But the “pure” physically based representation of hair (and other animation elements) is not the only concern of the animators, who want to “control” the creation and animation phases of the content. This paper describes a sketch-based tool, with which a user can both create hair models with different styling parameters and produce animations of these created hair models using physically and key frame-based techniques. The model creation and animation production tasks are all performed with direct manipulation techniques in real-time. 相似文献
2.
In addition to the classical heuristic algorithms of operations research, there have also been several approaches based on artificial neural networks for solving the traveling salesman problem. Their efficiency, however, decreases as the problem size (number of cities) increases. A technique to reduce the complexity of a large-scale traveling salesman problem (TSP) instance is to decompose or partition it into smaller subproblems. We introduce an all-neural decomposition heuristic that is based on a recent self-organizing map called KNIES, which has been successfully implemented for solving both the Euclidean traveling salesman problem and the Euclidean Hamiltonian path problem. Our solution for the Euclidean TSP proceeds by solving the Euclidean HPP for the subproblems, and then patching these solutions together. No such all-neural solution has ever been reported. 相似文献
3.
The effect of categorizing returned products in remanufacturing 总被引:1,自引:0,他引:1
An increasing number of companies have been implementing comprehensive recycling and remanufacturing programs. These endeavors typically involve the operation of joint manufacturing and remanufacturing systems. One of the major challenges in managing such hybrid systems is the stochastic nature of product returns. In particular, there is significant variability in the condition of the returns. This paper presents an approach for assessing the impact of quality-based categorization of returned products. Through extensive numerical studies on a continuous-time Markov chain model, we show that incorporation of returned product quality in the remanufacturing and disposal decisions can lead to significant cost savings. We find that these savings are amplified as the return quality decreases, and as the return rate increases. We also show that prioritizing higher quality returns in remanufacturing is, in general, a better strategy. 相似文献
4.
Aras Kartouzian 《Nanoscale research letters》2013,8(1):339
A bottom-up approach to nanofabricate metallic glasses from metal clusters as building blocks is presented. Considering metallic glasses as a subclass of cluster-assembled materials, the relation between the two lively fields of metal clusters and metallic glasses is pointed out. Deposition of selected clusters or collections of them, generated by state-of-the-art cluster beam sources, could lead to the production of a well-defined amorphous material. In contrast to rapidly quenched glasses where only the composition of the glass can be controlled, in cluster-assembled glasses, one can precisely control the structural building blocks. Comparing properties of glasses with similar compositions but differing in building blocks and therefore different in structure will facilitate the study of structure–property correlation in metallic glasses. This bottom-up method provides a novel alternative path to the synthesis of glassy alloys and will contribute to improving fundamental understanding in the field of metallic glasses. It may even permit the production of glassy materials for alloys that cannot be quenched rapidly enough to circumvent crystallization. Additionally, gaining deeper insight into the parameters governing the structure–property relation in metallic glasses can have a great impact on understanding and design of other cluster-assembled materials. 相似文献
5.
The processes of gas evolution at electrodes in electrochemical reactors and of boiling belong to strongly different fields in chemical engineering and for a long time were investigated separately. Nonetheless, they exhibit numerous common features. The analogies of both processes have been made use of giving rise to transfer findings obtained in one field to the other one. However, the analogy is limited, and the limitations have not yet attracted sufficient interest. A brief review on the analogies is given. The discrepancies in the fields of initial nucleation, the upper bound of operation and the different mechanisms controlling the transport of substance and of heat in both processes are discussed. 相似文献
6.
Synthesis and characterization of waterborne and phosphorus-containing flame retardant polyurethane coatings 总被引:2,自引:0,他引:2
Funda ?elebi Leyla Aras Güng?r Gündüz Idris M. Akhmedov 《Journal of Coatings Technology》2003,75(944):65-71
Phosphorus-containing flame retardant water-dispersed polyurethane coatings were produced by incorporating different amounts
of a phosphorus compound onto the polyurethane main chain. The novel phosphorus containing compound (phosphorus phenyl dihydroxy)
was synthesized in three steps using benzaldehyde, pentaerythritol, phenyl phosphonic dichloride, and acetic acid.
The addition of phosphorus phenyl dihydroxy to the main chain of polyurethane, in which NCO/OH ratio was kept constant at
1.5 and the amount of dimethylolpropionic acid (DMPA) at 3.5 wt%, increased the hardness and abrasion resistance, but only
slightly decreased the gloss values of the polyurethane paints. All the samples showed superior impact resistance and flexibility.
Moreover, increasing the phosphorus content increased the char yield, and the maximum fire retardancy was reached at 1.5%
P content with a limiting oxygen index (LOI) value of 29.
Kimya B?lümü, 06531 Ankara, Turkey. 相似文献
7.
Aydn Aras 《Applied Clay Science》2004,24(3-4):257
Raw material for ceramics consists mainly of kaolinite, illite, quartz and feldspar. Three representative clays, a high kaolinitic (HB), illitic- and quartz-rich (KW) and naturally mixed kaolinite–illite (P1) clays of Westerwald area, were chosen for this study [Kromer, H., 1980. Tertiary clays in the Westerwald area. Geol. Jb. D. Rhei D Hanover, 69–84]. The largest and oldest clay mining area of Germany is in the Westerwald area. These clays were mixed with each other and also with K, and Ca–Na feldspar. The high temperature phases of the mixed bodies were of three groups: crystalline phase, amorphous/glassy phase and porosity.The aim of this study was to determine: (1) the effect of kaolinite–illite–quartz ratios, (2) the effect of heat treatment and (3) the effect of feldspar on the fired mineralogy of the fired products. The crystalline phases are cristobalite, mullite, quartz, hematite and anatase. The bodies consist of crystalline phases such as quartz, mullite and cristobalite in a composite structure where crystals and pores are often embedded in amorphous/glassy phase. The formation of mullite and cristobalite is very distinctive in kaolinitic clay, and the structure is dominated by the spiky primary mullite. In the illite/sericite-rich mixtures, the high K content causes a large amount of melt superimposed on the mullite formation. The cristobalite formation is completely suppressed in illite/sericite-rich bodies. After dehydroxylation, metakaolinite and illite/sericite anhydride structures are formed. The persistence of illite/sericite anhydride peaks above 950 °C in KW clay indicates the presence of sericite/muscovite mineral. The disappearance temperatures and firing behaviour of K and Ca–Na feldspar observed within the XRD patterns of mixed bodies are different. K feldspar lines disappear earlier in HB bodies than in KW bodies, but Ca–Na feldspar shows a reverse behaviour. While Ca–Na feldspar peak intensity gradually decreases but persists at 1150–1250 °C, K feldspar suddenly disappears at 1150 °C. 相似文献
8.
Enriched stable isotopes are being increasingly used for study of trace element nutrition in humans who cannot be studied by use of in vivo radioactive tracers (e.g., subjects under age 18 and pregnant women). Zinc metabolism in these subjects can be evaluated by administration of Zn enriched to 65% in the minor isotope, 70Zn (0.6% natural abundance). The enhanced 70Zn is detected later in red blood cells, plasma, urine, and feces by measuring 70Zn/64Zn or 70Zn/68Zn ratios. Stable isotope concentrations are measured by neutron activation of the samples and observation of their products: 244-day 65Zn, 14-h 69mZn, and 4-h 71mZn. Zinc-65 can be observed in these samples without chemical separations 3 weeks after irradiations, but large amounts of 24Na and other short-lived species preclude direct observation of the short-lived Zn activities. Preirradiation chemistry was developed to remove most interferences, the major steps being to place the sample on Chelex resin, elute alkali metals and alkaline earths from it, and irradiate the resin containing the Zn. gamma-Rays of 69mZn can be observed on the irradiated resin, but additional precipitation and solvent extraction steps are needed to remove 56Mn and 64Cu for clear observation of 71mZn and 65Zn within hours after irradiation. Yields for pre- and postirradiation separations are typically 85% and 70%, respectively. The stable isotope tracer method was validated by simultaneous in vivo tracing with radioactive 65Zn in four subjects. 相似文献
9.
The increase in negative effects of fossil fuels on the environment has forced many countries, especially the developed ones, to use renewable energy sources. Currently the fastest developing energy source technology is wind energy. Because wind energy is renewable and environment friendly, systems that convert wind energy to electricity have developed rapidly. Wind energy is an alternative clear energy source compared to the fossil fuels that pollute the lower layer of atmosphere. Because wind energy will be used more and more in the future, its current potential, usage, and assessment in Turkey is the focus of this study. 相似文献
10.
Petrulis Aras; DeSouza Ian; Schiller Marisa; Johnston Robert E. 《Canadian Metallurgical Quarterly》1998,112(1):199
Orbital/agranular insular (ORB/AI) cortex has been implicated in traditional olfactory learning tasks and social behavior but its precise role in discriminating-learning social odors is not known. Female golden hamsters received aspiration lesions of ORB/AI or dorsomedial (DM) frontal cortex and were tested for their ability to (a) discriminate between odors of individual males in a habituation-discrimination task, (b) show preferences for male over female odors, and (c) scent-mark in response to male odors. Lesioned females readily discriminated between scents of individual males. Neither lesion altered female preferences for male odors. Females with DM lesions showed increased levels of scent marking to male odors, but those with ORB/AI cortex lesions did not differ from controls. Thus, ORB/AI cortex does not appear to be critical for discrimination of odors of individuals or sex or for scent-marking responses based on these discriminations. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献